Power supply device and vacuum processing apparatus using the same

ABSTRACT

A power supply device supplies power to a substrate holder having a plurality of electrodes. The device includes a first fixed conductive member, a second fixed conductive member, a fixed insulating member fixed to an insulating housing portion and configured to insulate the first fixed conductive member from the second fixed conductive member, a first rotation conductive member, a second rotation conductive member, a rotation insulating member fixed to an insulating column portion and configured to insulate the first rotation conductive member from the second rotation conductive member, a first power supply member configured to supply a first voltage to the substrate holder via the first rotation conductive member and the first fixed conductive member, and a second power supply member configured to supply a second voltage to the substrate holder via the second rotation conductive member and the second fixed conductive member.

This application is a continuation of International Patent ApplicationNo. PCT/JP2012/005570 filed on Sep. 3, 2012, and claims priority toJapanese Patent Application No. 2011-272359 filed on Dec. 13, 2011, theentire content of both of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a power supply device and a vacuumprocessing apparatus using the same. More particularly, the presentinvention relates to a power supply device suitable for supplying powerto the electrostatic chuck of a substrate holder arranged rotatably in avacuum processing chamber and a vacuum processing apparatus using thepower supply device.

BACKGROUND ART

A conventional power supply device will be described below withreference to FIGS. 7A and 7B. In the arrangement disclosed in PTL 1, forexample, as shown in FIG. 7A, a substrate holder 601 of a power supplydevice is held to be rotatable inside a vacuum vessel 630. The substrateholder 601 has a slidable surface using surface contact about a rotationaxis C of a rotation column 602 as its center between the rotationcolumn 602 and a base 603 which supports the load of the rotation columnof the substrate holder 601. A rotary joint made of a plurality ofconductive annular members 604 arranged concentrically is arranged tomake it possible to stably supply the power to the electrode of theelectrostatic chuck without causing unstable rotation of the substrateholder 601. As for a bipolar electrostatic chuck for supplying power toa plurality of electrodes, a plurality of rotary joints are aligned inthe rotation axis direction to sandwich insulating members 605 a and 605b between the adjacent rotary joints, thereby maintaining the insulatingstate between the plurality of electrodes.

To obtain a stable rotation operation in this structure, the insulatingmembers 605 a and 605 b are arranged on the side of the rotation column602 of the substrate holder 601 and on the side of the base 603 whichsupports the load of the rotation column and the like. A minimum gap 607must be formed between the insulating members. The rotary joint has anincomplete sealing property, and a very small amount of liquid may leakfrom the rotary joint. A drain port is generally formed to drain theleaking liquid outside

CITATION LIST Patent Literature

PTL 1: Japanese Patent Laid-Open No. 2008-156746

SUMMARY OF INVENTION Technical Problem

However, in addition to the substrate holder by which a substrate isheld horizontally with respect to the ground, as shown in FIG. 7A, therehave recently increased substrate processing apparatuses each capable ofturning a substrate holder in a state in which the normal to thesubstrate holding surface of the substrate holder is perpendicular tothe gravity direction for a larger substrate and space saving of thesubstrate processing apparatus. In such a substrate processingapparatus, it is often difficult to drain, from the drain port, theliquid leaking from the rotary joint.

For example, even if the resistivity of pure water flowing through theinternal channel is managed to be 10 MΩ·cm or more, the resistivity ofthe pure water leaking from the rotary joint drops soon. This results inthe presence of the liquid having a low resistivity between theplurality of electrodes. In some cases, the plurality of electrodes canelectrically be connected through this liquid.

The present invention has been made in consideration of the aboveproblem, and has as its object to provide a power supply device usablein a processing apparatus which turns a substrate holder in a state inwhich the normal to the substrate holding surface of a substrate holderis perpendicular to the gravity direction.

Solution to Problem

In order to achieve the above object according to the present invention,there is provided a power supply device comprising a substrate holdercapable of holding a substrate, a column connected to the substrateholder and including a first conductive column portion and a secondconductive column portion, a housing rotatably supporting the column andincluding a first conductive housing portion and a second conductivehousing portion, a first conductive portion configured to supply a firstvoltage from the first conductive housing portion to the firstconductive column portion, a second conductive portion configured tosupply a second voltage from the second conductive housing portion tothe second conductive column portion, the second conductive portionbeing insulated from the first conductive portion, a first power supplymember connected to the first conductive column portion and configuredto supply the first voltage to the substrate holder, and a second powersupply member connected to the second conductive column portion andconfigured to supply the second voltage to the substrate holder, whereina first space in contact with the first conductive portion and capableof flowing a coolant and a second space in contact with the secondconducive portion and capable of flowing the coolant are formed in a gapbetween the column and the housing, and the power supply device furthercomprises separating means for separating the first space from a memberapplied with the second voltage and separating the second space from amember applied with the first voltage.

Advantageous Effects of Invention

The present invention can be applied to a substrate processing apparatusin which the substrate holder is turned in a state in which the normalto the substrate holding surface of the substrate holder isperpendicular to the gravity direction, thereby stably supplying powerto the substrate holder having a plurality of electrodes.

Other features and advantages of the present invention will be apparentfrom the following descriptions taken in conjunction with theaccompanying drawings, in which like reference characters designate thesame or similar parts throughout the figures thereof.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention.

FIG. 1 is a schematic sectional view of an ion beam etching apparatushaving a power supply device according to the first embodiment of thepresent invention when viewed from its side surface;

FIG. 2 is a sectional view when viewed from a line X-X in FIG. 1;

FIG. 3A is a view for explaining a fluid channel for circulating acoolant;

FIG. 3B is a view showing the details of a power supply mechanism shownin FIG. 2;

FIG. 4A is a view showing the section along a line Z-Z of FIG. 3A;

FIG. 4B is a view showing the section along a line Y-Y of FIG. 3A;

FIG. 5 is a schematic view showing the current path of a power supplydevice shown in FIG. 3B;

FIG. 6A is a view for explaining a fluid channel for circulating acoolant of a power supply device and a power supply path according tothe second embodiment of the present invention;

FIG. 6B is a view for explaining a fluid channel for circulating thecoolant of the power supply device and the power supply path accordingto the second embodiment of the present invention;

FIG. 7A is a view for explaining a conventional power supply device; and

FIG. 7B is a view for explaining the conventional power supply device.

DESCRIPTION OF EMBODIMENTS

The embodiments of the present invention will be described below withreference to the accompanying drawings. Note that members and layouts tobe described below are merely examples, and will not limit the presentinvention. Various modifications can be made within the scope of thepresent invention, as a matter of course. Note that the same referencenumerals throughout the accompanying drawings to be described belowdenote the same functions, and a repetitive explanation will be omitted.

This embodiment will exemplify an ion beam etching apparatus as a vacuumprocessing apparatus, but the scope of the present invention is notlimited to this example. For example, a power supply device according tothe present invention is applicable to a vacuum processing apparatussuch as another etching apparatus, sputtering deposition apparatus, PVDapparatus, or CVD apparatus.

First Embodiment

FIG. 1 is a schematic sectional view of an ion beam etching apparatushaving a power supply device when viewed from the side surface accordingto the present invention. FIG. 2 is a sectional view along a line X-X ofFIG. 1. FIGS. 3A and 3B are views showing the details of a power supplymechanism 30 (power supply device) shown in FIG. 2. Note that somemembers are not illustrated to prevent complication of the accompanyingdrawings. An ion beam etching apparatus 1 is an apparatus forirradiating a substrate W placed on a substrate stage 7 with ionsemitted by an ion beam source 5 and etching a stacked film formed on thesubstrate W.

The ion beam etching apparatus shown in FIG. 1 includes, in a vacuumvessel 3 (vacuum processing chamber), the ion beam source 5 serving asan etching source, the substrate stage 7, and a shutter device 9. Theion beam source 5 is arranged on the side surface of the vacuum vessel3. The substrate stage 7 is arranged to oppose the ion beam source 5.

The substrate stage 7 includes, as constituent components, a substrateholder (to be referred to as a substrate holding portion 7 ahereinafter) for holding the substrate W and a housing (to be referredto as a rotation support portion 7 b) for supporting the substrateholding portion 7 a. The rotation support portion 7 b is supported bythe vacuum vessel 3. The substrate holding portion 7 a can attract andhold the substrate W by an electrostatic chuck mechanism. The substrateholding portion 7 a can rotate together with the substrate W. Therotation support portion 7 b is pivotal about a rotation axis B (firstrotation axis) as the rotation center. The rotation support portion 7 bcan change the direction of the substrate holding portion 7 a opposingthe ion irradiation surface of the ion beam source 5. That is, the angleof the substrate etching surface with respect to the incident directionof ions emitted by the ion beam source 5 can be changed. By changing theincident angle of the ions on the substrate etching surface, the ionscan enter the etching surface of the substrate W from an obliquedirection, thereby performing accurate etching.

The ion beam source 5 is a unit for irradiating the substrate W withions obtained by ionizing a gas with a plasma. In this embodiment, Argas is ionized. However, ions to be radiated are not limited to Ar ions.For example, a Kr gas, Xe gas, O₂ gas, or the like can be used. Aneutralizer (not shown) for neutralizing charges of the ions emitted bythe ion beam source 5 is arranged on the side wall surface of the ionbeam source 5.

The shutter device 9 is arranged between the ion beam source 5 and thesubstrate W on the substrate stage 7. The opening/closing operation ofthe shutter device 9 can block the ions emitted by the ion beam source 5to the substrate W before the ions reach the substrate W.

The interior of the substrate stage 7 will now be described withreference to FIG. 2. The rotation support portion 7 b is a stagerotatable about the rotation axis B (first rotation axis). The substrateholding portion 7 a is a substrate support table having an electrostaticattraction mechanism rotatable about a rotation axis A (second rotationaxis) in a direction perpendicular to the rotation axis B (firstrotation axis). The substrate can be placed on the substrate holdingportion 7 a by the attraction operation of the electrostatic attractionmechanism. The rotation support portion 7 b is arranged in the vacuumvessel 3, and the substrate holding portion 7 a is coupled to one end ofthe rotation support portion 7 b. A rotation column 25 (column) iscoupled to the lower surface (that is, a surface opposite to the surfaceon which the substrate is held) of the substrate holding portion 7 a.The rotation column 25 made of a conductive material is rotatablymounted, through a vacuum seal mechanism 26 such as a magnetic fluidseal, in a hole portion formed in one end of the rotation supportportion 7 b. This makes it possible to maintain the interior of thevacuum vessel 3 in a hermetic state. The substrate holding portion 7 afixed to the rotation column 25 rotates together with the substrate Wheld by the substrate holding portion 7 a by a rotation mechanism(rotation driving device 27). The power supply mechanism 30 includes afirst rotation driving device for rotating the rotation support portion7 b about the rotation axis B (first rotation axis) and a secondrotation driving device for rotating the substrate holding portion 7 aabout the rotation axis A (second rotation axis) in a directionperpendicular to the rotation axis B (first rotation axis).

For example, the rotation driving device 27 is arranged on a sideopposite to the substrate holding portion 7 a when viewed from thevacuum seal mechanism 26. The rotation driving device 27 functions as amotor for rotating the rotation column 25 by the interaction between amagnet (not shown) attached to the rotation column 25 and anelectromagnet (not shown) arranged around the magnet. An encoder (notshown) for detecting the rotation speed and rotation direction of therotation column 25 is added to the rotation driving device 27.

The substrate holding portion 7 a includes a dielectric plate 23 havinga holding surface for holding the substrate W and an electrostatic chuck(electrostatic attraction device) 24 for attracting the substrate W withan electrostatic attraction force to the dielectric plate 23 and fixingit to the dielectric plate 23. In addition, a fluid channel (not shown)for supplying a heat conduction lower surface gas to the lower surfaceside of the substrate W fixed on the dielectric plate 23 by theelectrostatic chuck 24 is formed in the substrate holding portion 7 a. Asupply port communicating with the fluid channel is formed in the vacuumseal mechanism 26. The lower surface gas is a gas by which heat isefficiently conducted from the substrate W to the substrate holdingportion 7 a cooled by a coolant. Conventionally, argon gas (Ar) ornitrogen gas is used. Note that cooling water for cooling the lowersurface side of the substrate W is supplied to the substrate holdingportion 7 a through a cooling water supply pipe 63 shown in FIGS. 4A, 4Band 5 (to be described later), and drained through a cooling water drainpipe 59.

The electrostatic chuck 24 is a positive and negative, bipolar chuckdevice and includes two electrodes 28 a and 28 b. The electrode 28 a ofone polarity and the electrode 28 b of the other polarity are embeddedin plate-like insulating members, respectively. A predetermined firstvoltage is supplied to the electrode 28 a via a power supply rod 29 a(first power supply member) arranged inside the substrate holdingportion 7 a and the rotation column 25. A predetermined second voltageis supplied to the electrode 28 b via a power supply rod 29 b (secondpower supply member) arranged inside the substrate holding portion 7 aand the rotation column 25. The two power supply rods 29 a and 29 bextend to the lower portion of the rotation column 25, as shown in FIG.2. The power supply rods 29 a and 29 b are covered with insulatingmembers 31 a and 31 b, respectively.

The power supply mechanism 30 (power supply device) is arranged midwayalong the rotation column 25 to supply different voltages (for example,two different bias voltages) for electrostatic attraction from anexternal power supply to the two electrodes 28 a and 28 b of theelectrostatic chuck 24. In order to prevent a state in which the powersupply mechanism 30 is electrically connected to the vacuum sealmechanism 26 and the rotation driving device 27 through the rotationcolumn 25, insulating members 64 are arranged at one end and the otherend, respectively, of a portion of the rotation column 25 extendingthrough the power supply mechanism 30. The power supply mechanism 30 anda first voltage power supply 71 a for supplying the first voltage (forexample, a DC bias voltage or RF voltage) are connected to an insulatedcable 33 a (first voltage supply line). The power supply mechanism 30and a second voltage power supply 71 b for supplying a second voltage(for example, a DC bias voltage or RF voltage) are connected to aninsulated cable 33 b (second voltage supply line). These cables 33 a and33 b are connected in a loose state so as not to be disconnected even ifthe unit is rotated and twisted about the rotation axis B. A rotaryjoint 36 is arranged in the power supply mechanism 30. The details ofthe rotary joint 36 will be described later.

A rotation cylinder 32 is rotatable about the rotation axis B. Therotation support portion 7 b is fixed to the rotation cylinder 32. Therotation cylinder 32 is rotatably mounted, through a vacuum sealmechanism 34 such as a magnetic fluid seal, in a hole portion formed inthe vacuum vessel 3. This makes it possible to maintain the interior ofthe vacuum vessel 3 in a hermetic state. For example, a servo motor (notshown) can rotate the rotation cylinder 32.

The power supply mechanism 30 of the rotary joint 36 (36 a and 36 b)will be described in detail with reference to FIGS. 3A and 3B. Therotary joint 36 a (first conductive portion) includes a conductiveannular member 37 a (first rotation conductive member) and a conductiveannular member 39 a (first fixed conductive member). The conductiveannular member 37 a is fixed to a rotation column 101 a (firstconductive column portion) made of a conductive material and fixed tothe rotation column 25. The conductive annular member 37 a is arrangedso that its center matches the center of the rotation axis A. Theconductive annular member 39 a is fixed to a housing 38 a (firstconductive housing portion) made of a conductive material. Theconductive annular member 39 a is arranged so that its center matchesthe center of the rotation axis A. The housing 38 a is an annular memberso that its center matches the center of the rotation axis A.

The conductive annular members 37 a and 39 a are arranged in slidablesurface contact with an annular portion 130. The conductive annularmember 39 a is biased against the conductive annular member 37 a by anelastic member 135 (for example, a leaf spring, coil spring, or rubbermember). The elastic member 135 functions as an auxiliary mechanism forholding the hermetic state (seal property) of the sliding annularportion 130. When the rotation column 25 rotates, the conductive annularmember 37 a and the conductive annular member 39 a are in slidablecontact at the rotary joint 36 a. The housing 38 a is fixed to therotation support portion 7 b and connected to the first voltage powersupply 71 a via the conductive cable 33 a the surface of which iscovered with an insulating film material.

Similarly, the rotary joint 36 b (second conductive portion) includes aconductive annular member 37 b (second rotation conductive member) and aconductive annular member 39 b (second fixed conductive member). Theconductive annular member 37 b is fixed to a rotation column 101 b(second conductive support portion) made of a conductive material andfixed to the rotation column 25. The conductive annular member 37 b isarranged so that its center matches the center of the rotation axis A.The conductive annular member 39 b is fixed at a position spaced apartfrom a position where the conductive annular member 39 a (first fixedconductive member) in the housing 38 a is fixed. The conductive annularmember 39 b is arranged so that its center matches the center of therotation axis A. The conductive annular members 37 b and 39 b arearranged in slidable surface contact with an annular portion 139. Theconductive annular member 39 b is biased against the conductive annularmember 37 b by an elastic member 137 (for example, a leaf spring, coilspring, or rubber member). The elastic member 137 functions as anauxiliary mechanism for holding the hermetic state (seal property) ofthe sliding annular portion 139.

A rotary joint 1036 (insulating seal portion) includes an annular member1037 (rotation insulating member) and an annular member 1039 (fixedinsulating member). The annular members 1037 and 1039 are membershaving, for example, a resistivity of 1 MΩ·cm or more. In thisembodiment, in consideration of the seal performance, silicon carbidehaving a high wear resistance is used as the annular members 1037 and1039. The annular member 1037 is fixed around a rotation column 45 a(insulating column portion) made of an insulating material and fixed tothe rotation column 25. The annular member 1037 is arranged at aposition on a concentric circle using the rotation axis A as the center.The annular member 1037 is arranged at a position spaced apart from therotation columns 101 a and 101 b and set in an electrically floatingstate. The annular member 1039 is fixed to a housing 45 b (insulatinghousing portion) made of an insulating material and arrangedconcentrically with the rotation column 45 a using the rotation axis Aas the center. The annular member 1039 is arranged at a position spacedapart from the housing 38 a and a housing 38 b and set in anelectrically floating state. The annular members 1037 and 1039 arearranged in slidable surface contact with an annular portion 138. Theannular member 1039 is biased against the annular member 1037 by anelastic member 136. The elastic member 136 functions as an auxiliarymechanism for holding the hermetic property (seal property) of thesliding annular portion 138.

When the rotation column 25 rotates, the conductive annular member 37 band the conductive annular member 39 b slide with the rotary joint 36 b.The housing 38 b is fixed to the rotation support portion 7 b andconnected to the second voltage power supply 71 b via the conductivecable 33 b the surface of which is covered with an insulating film. Whenthe rotation column 25 rotates, the annular members 1037 and 1039 slidewith the rotary joint 1036.

The power supply mechanism 30 can apply a DC bias power to theelectrostatic chuck 24. The power supply mechanism 30 is electricallydivided into two zones by the first insulating member 45 a (rotationinsulating member) sandwiched between the rotation columns 101 a and 101b and the second insulating member 45 b (fixed insulating member)sandwiched between the housings 38 a and 38. The two divided zones arearranged in series using the rotation axis B as the center through thefirst insulating member 45 a and the second insulating member 45 b.

One of the two electrodes of the electrostatic chuck 24 is electricallyconnected to one of the regions of the power supply mechanism 30 dividedby the first insulating member 45 a and the second insulating member 45b. The other of the two electrodes of the electrostatic chuck 24 iselectrically connected to the other of the divided regions. The powersupply mechanism 30 is divided by the first insulating member 45 a andthe second insulating member 45 b into a divided region 30 a closer tothe electrostatic chuck 24 and a divided region 30 b far from theelectrostatic chuck 24. The divided regions 30 a and 30 b are insulatedfrom each other. The electrode 28 a of the electrostatic chuck 24 andthe divided region 30 a are electrically connected via the power supplyrod 29 a which is formed in the rotation column 25 made of a conductivematerial and is covered with the insulating member 31 a.

The electrode 28 of the electrostatic chuck 24 and the divided region 30b are electrically connected via the power supply rod 29 b formed in therotation column 25 and covered with the insulating member 31 b. Thepower supply rod 29 b is covered with the insulating member 31 b in thedivided region 30 b.

The power supply mechanism 30 includes the rotation columns 101 a and101 b and the housings 38 a and 38 b arranged around the rotationcolumns 101 a and 101 b. The power supply mechanism 30 includes thefirst and second insulating members 45 a and 45 b which divide the powersupply mechanism 30 into the divided regions 30 a and 30 b. The powersupply mechanism 30 further includes the rotary joints 36 a and 36 bmade of a conductive material and serving to slide the rotation columns101 a and 101 b and the housings 38 a and 38 b. The, rotation column 101a (first conductive column portion), the first insulating member 45 a(insulating column portion), and the rotation column 101 b (secondconductive column portion) shown in FIG. 3B are integrated to form therotation column 25 (FIG. 2). The housings 38 a and 38 b (first andsecond conductive housing portions) and the second insulating member 45b (insulating housing portion) shown in FIG. 3B are integrated to formthe housing 38 (FIG. 2).

The power supply rod 29 a electrically connects the electrode 28 a andthe divided region 30 a corresponding to the electrode 28 a while aregion extending from the electrode 28 a of the electrostatic chuck 24to the divided region 30 a corresponding to the power supply mechanism30 is kept insulated. The power supply rod 29 b electrically connectsthe electrode 28 b and the divided region 30 b corresponding to theelectrode 28 b while a region extending from the electrode 28 b of theelectrostatic chuck 24 to the divided region 30 b corresponding to thepower supply mechanism 30 is kept insulated.

The divided region 30 a is electrically connected to the conductivehousing 38 a through the conductive rotary joint 36 a. The housing 38 ais electrically connected to the first voltage power supply 71 a. Thefirst voltage is applied from the first power supply 71 a to the housing38 a. The divided region 30 b is electrically connected to theconductive housing 38 b through the conductive rotary joint 36 b. Thehousing 38 b is electrically connected to the second voltage powersupply 71 b. The second voltage is applied from the second voltage powersupply 71 b to the housing 38 b.

According to this embodiment, an electrical path for supplying power tothe electrostatic chuck 24 can be included in the rotation column 25.Without routing electrical wires and the like, the power supply path tothe electrostatic chuck can be ensured. In addition, since theelectrical path can be included in the rotation column 25, the cables ofthe electrical circuits are not entangled even if the substrate holdingportion 7 a is rotated.

In this embodiment, the power supply mechanism 30 is divided into twodivided regions 30 a and 30 b insulated from each other. The electrode28 a and the divided region 30 a are electrically connected while aregion extending from the electrode 28 a to the divided region 30 a iskept insulated. The electrode 28 b and the divided region 30 b areelectrically connected while a region extending from the electrode 28 bto the divided region 30 b is kept insulated. With this structure, powercan be properly supplied from each power supply to the electrostaticchuck 24 without shorting the positive and negative voltages supplied tothe electrostatic chuck 24.

A fluid channel for circulating a coolant for cooling the substrateholding portion 7 a will be described with reference to FIGS. 3A, 4A,and 4B. FIG. 3A is a view showing another section of the power supplymechanism 30 described with reference to FIG. 3B. FIG. 4A is a viewshowing the section along a line Z-Z of FIG. 3A. FIG. 4B is a viewshowing the section along a line Y-Y of FIG. 3A.

A coolant supply mechanism (not shown) circulates, as a coolant, purewater (cooling water) managed to have a resistivity of 1 MΩ·cm or more.The cooling water flows in from the cooling water inlet shown in FIG. 4Band flows in a channel (first channel) as indicated by an arrow 53. Thepure water (cooling water) is supplied from the cooling water supplypipe 63 to the substrate holding portion 7 a through a through hole (notshown) extending through in the rotation column 25 in FIG. 2. Note thatthe cooling water supply pipe 63 is a pipe-like insulating membercommunicating with a portion extending from the first insulating member45 a (rotation insulating member) to the substrate holding portion 7 a(substrate holder). O-rings 101 made of an elastomer material seal thepipe-like cooling water supply pipe 63 appropriately in the firstinsulating member 45 a.

The pure water (cooling water) supplied to the substrate holding portion7 a through the cooling water inlet, the cooling water supply pipe 63,and the through hole in the rotation column 25 flows in a cooling watercirculation channel (not shown) formed inside the substrate holdingportion 7 a. The pure water (cooling pipe) flows into the cooling waterdrain, pipe 59 shown in FIG. 4A through a through hole (not shown) inthe rotation column 25. The pure water is then drained from the coolingwater outlet. The cooling water drain pipe 59 is a pipe-like insulatingmember which communicates with a region from the substrate holdingportion 7 a to the first insulating member 45 a (rotation insulatingmember). O-rings 101 made of an elastomer material seal the pipe-likecooling water drain pipe 59 appropriately in the first insulating member45 a. The pure water (cooling water) from the substrate holding portion7 a flows in a channel (second channel) as indicated by an arrow 54 inFIG. 4A. The pure water (cooling water) then returns from the coolingwater outlet to a coolant supply mechanism (not shown) by a pipe member(not shown) and drains outside the power supply mechanism. Thisstructure can make it possible to prevent the cooling water from leakinginside the divided regions 30 a and 30 b when the coolant (coolingwater) flows in the channel. As shown in the rotary joint 36 b of FIG.3A, an O-ring 102 is arranged to seal between members to prevent leakageof the cooling water from the channel, thereby preventing cooling waterleakage from the channel. An O-ring 104 is arranged to achieve the samepurpose as described above.

A rubber seal member 103 a such as an oil seal is arranged ahead of thesliding portion between the conductive annular members 37 a and 39 a inslidable contact to prevent leakage of cooling water (coolant) in asmall amount at the sliding portion. In order to dry leaking coolingwater (coolant), a gas supply mechanism (not shown) supplies a dryinggas from a drying air inlet port 300 (FIG. 3A) and exhausts the gas froma drying air outlet 320 (FIG. 3B) toward a gas collection mechanism (notshown), thereby collecting the gas. A gas channel (third channel)communicating with the drying air inlet port 300 supplies the gas from agas supply mechanism (now shown) outside the conductive annular members37 a and 39 a to the interior of a space 201. The gas supplied from thegas channel (third channel) is exhausted toward the gas collectionmechanism (not shown) through a gas channel (fourth channel)communicating with the drying air outlet 320.

A drying air inlet port 310 (FIG. 3A) and a drying air outlet 330 (FIG.3B) are formed in a space formed by the conductive annular member 37 b,the conductive annular member 39 b, and a rubber seal member 103 b. Agas channel (fifth channel) communicating with the drying air inlet port310 supplies the gas from a gas supply mechanism (not shown) outside theconductive annular members 37 b and 39 b to the interior of a space 202.The gas supplied from the gas channel (fifth channel) is exhaustedtoward a gas collection mechanism (not shown) through a gas channel(sixth channel) communicating with the drying air outlet 330. The dryinggas from the drying air inlet ports 300 and 310 is supplied to dry theleaking coolant (cooling water) of the cooling water (coolant) stoppedby the sliding portion.

Referring to FIG. 3A, the space 201 (first space) is a space formed in agap between the rotation column 25 and the housing 38 a to flow thecoolant to be drained. More specifically, the space 201 is formed by theouter surface of the rotation column 101 a, the inner surface of thehousing 38 a which faces the outer surface of the rotation column 101 a,the conductive annular member 37 a, the annular member 1037, theconductive annular member 39 a, the annular member 1039, the firstinsulating member 45 a, and second insulating member 45 b. The interiorof the space 201 (coolant drain space) is kept in a hermetic state. Thespace 201 (first space) is formed to be spaced apart from the outersurface of the rotation column 101 b, the inner surface of the housing38 b, the conductive annular member 37 b, and the conductive annularmember 39 b. For this reason, the coolant in the space 201 does notcontact a member applied with a voltage different from the voltage(first voltage) applied to the housing 38 a and the like. The space 201forms a channel for flowing out the coolant (cooling water) from thecooling water drain pipe 59 shown in FIG. 4A to the cooling wateroutlet.

The space 202 (second space) is a space formed in a gap between therotation column 25 and the housing 38 b to flow the supplied coolant.More specifically, the space 202 is formed by the outer surface of therotation column 101 b, the inner surface of the housing 38 b which facesthe outer surface of the rotation column 101 b, the conductive annularmember 37 b, the annular member 1037, the conductive annular member 39b, and the annular member 1039. The interior of the space 202 is held ina hermetic state. The space 202 (second space) is formed to be spacedapart from the outer surface of the rotation column 101 a, the innersurface of the housing 38 a, the conductive annular member 37 a, and theconductive annular member 39 a. For this reason, the coolant in thespace 202 does not contact a member applied with a voltage differentfrom the voltage (second voltage) applied to the housing 38 b and thelike. The space 202 forms a channel for flowing the coolant (coolingwater) from the cooling water inlet shown in FIG. 4B to the coolingwater supply pipe 63.

When the coolant (cooling water) is circulated in the spaces 201 and 202formed by the rotary joints 36 a, 36 b, and 1036, this results indissipating heat generated by the respective rotary joints 36 a, 36 b,and 1036. The sliding property between the sliding annular members canalso be improved, thereby greatly prolonging the lifetime of eachannular member.

Strictly speaking, the electrical connection between the divided regions30 a and 30 b forms an electrical circuit shown in FIG. 5. Morespecifically, this circuit is a series circuit via the pure waterpresent in the space 201 and the annular members 1037 and 1039 and thepure water present in the space 202. The pure water in the space 201,the pure water in the space 202, and the annular members 1037 and 1039have a very high resistance as compared with those of the conductivemembers. This contributes to maintaining the dielectric resistancebetween the divided regions 30 a and 30 b to a predetermined value ormore. However, when different voltages are supplied to the dividedregions 30 a and 30 b, respectively, a small amount of current flows viathe electrical circuit shown in FIG. 5. This small amount of currentdoes not immediately interfere with a bipolar voltage supplied necessaryfor electrostatic attraction. As is generally known, when a currentflows between conductive members through water, ions are deposited fromconductive members by electrolytic corrosion. This deposit is attachedto walls of the spaces 201 and 202 to result in a decrease in flow rateupon clogging. The electrical connection between the divided regions 30a and 30 b may occur through a conductive material attached to thewalls.

However, according to the structure of this specification, a currentgenerated between the divided regions 30 a and 30 b can be minimized.This makes it possible to minimize the conductive material deposition byelectrolytic corrosion, thereby greatly prolonging the maintenance timeinterval. The power supply device of this specification is more suitableif it meets the following conditions. More specifically, pure watermanaged to have a predetermined resistivity or more (1 MΩ·cm or more) isused as a coolant. Members having a resistivity of 1 MΩ·cm or more areused as the annular members 1037 and 1039 which partition the spaces 201and 202. In addition, the divided regions 30 a and 30 b will notelectrically contact each other.

A supply line of a coolant (cooling water) to the substrate holdingportion 7 a and a drain line of the coolant (cooling water) returningfrom the substrate holding portion 7 a are partitioned by surfacesliding portions slidable contact with the annular members 1039 and1037. Even if the coolant leaks from the coolant supply line side to thecoolant drain line side through the surface sliding portions, thecoolant (cooling water) stays in the circulation channel whoseresistance is managed to be a predetermined value or more by an ionexchange resin incorporated in a coolant supply mechanism (not shown).For this reason, the resistance of the electrical circuit shown in FIG.5 can be properly maintained without abruptly dropping the resistivityof the coolant (cooling water).

Second Embodiment

In the first embodiment described above, the power supply mechanism(power supply device) in which the plurality of conductive annularmembers 37 a, 39 a, 37 b, and 39 b are aligned in the rotation axisdirection of the substrate has been described. According to the secondembodiment, a power supply device in which a plurality of conductiveannular members 37 a, 39 a, 37 b, and 39 b are parallelly arranged in aradial direction of the rotation axis of the substrate, in other words,in a concentric manner using the rotation axis of the substrate as thecenter, as shown in FIGS. 6A and 6B will be described below. When theplurality of conductive annular members 37 a, 39 a, 37 b, and 39 b areparallelly arranged in concentric manner with respect to the rotationaxis of the substrate, the overall length of the power supply device canbe shorter than the conventional power supply device having a pluralityof polarities. The unit can be made compact. Note that the conductiveannular members of the second embodiment have dimensions and shapesdifferent from those of the conductive annular members 37 a, 39 a, 37 b,and 39 b in the first embodiment, but the same reference numerals as inthe first embodiment denote the same functions in the second embodiment.

FIG. 6A is a view for explaining a fluid channel for circulating thecoolant of the power supply device according to the second embodiment ofthe present invention. FIG. 6B is a view showing the power supplymechanism of the power supply device according to the second embodimentof the present invention. The power supply device of this embodiment hasa structure in which a plurality of conductive annular members areparallelly arranged in a concentric manner with respect to the rotationaxis of the substrate. A housing is formed to face an end portion (thatis, an end portion opposite to the substrate holder side) of a rotationcolumn (column). The channels and power supply rods extend through thewall surface of the housing opposing to the end portion of the rotationcolumn so that the coolant and the power supply pipe are accessible inthe rotation axis direction of the column. For the respective membersconstituting the power supply device according to the second embodiment,members having the same functions as in the first embodiment denote thesame reference numerals, and a detailed description thereof will not berepeated.

In the power supply device according to each of the first and secondembodiments, a pair of annular members 1037 and 1039 are provided as theseparation means. However, a plurality of pairs of annular members 1037and 1039 may be provided. In place of the annular members 1037 and 1039,two pairs of conductive annular members 37 a and 39 a of the rotaryjoints 36 a may be provided to flow the coolant between them. In thiscase, one pair of the conductive annular members 37 a and 39 a functionsas the separation means. Similarly, two pairs of conductive annularmembers 37 b and 39 b of rotary joints 36 b may be provided.

In the power supply device according to each of the first and secondembodiments, the annular members 1037 and 1039 are mounted in aninsulating rotation column 45 a and a housing 45 b. However, the annularmembers 1037 and 1039 may simply be mounted in rotation columns 101 aand 101 b and housings 38 a and 38 b. An insulating coating is formed onpart of the conductive member which contacts the coolant, therebyobtaining the effect of the present invention. For example, when theannular member 1037 and 1039 are arranged to contact the first andsecond voltages in a space 201, insulating coatings are formed on theconductive members applied with voltages different from the voltagesupplied to the rotation column 25 side contacting the space 201.

In the power supply device according to each of the first and secondembodiments, the coolant is supplied to a substrate stage 7 through therotation columns 101 a and 101 b. The power supply device of the presentinvention is applicable to a processing apparatus which does not cool asubstrate. In this case, the coolant supplied from the cooling waterinlet port is drained from the cooling water outlet through the rotationcolumn 45 a. A channel for connecting the space 201 and a space 202 isformed in the first insulating member 45 a. Alternatively, the coolingwater inlet and outlet may be formed in each of the housings 38 a and 38b, and the coolant components may be merged outside. In this case, achannel hole for cooling water need not be formed in the firstinsulating member 45 a.

The power supply device according to each of the first and secondembodiments is mounted in only the rotation column 25 of the ion beametching apparatus 1, but may be mounted in the rotation cylinder 32, asa matter of course. In this case, cables 33 a and 33 b will not twist.For example, the power supply device is applied to a processingapparatus which applies RF bias power. This can eliminate twisting ofthe cables 33 a and 33 b depending on the angle of the substrate holder,thereby further stabilizing the effect of applying the bias power.

The power supply device according to each of the first and secondembodiments includes one rotary joint 36 a (first conductive portion),one rotary joint 36 b (second conductive portion), and one rotary joint1036 (insulating seal portion). However, the power supply device mayinclude a plurality of rotary joints 36 a, a plurality of rotary joints36 b, and a plurality of rotary joints 1036. In this case, the rotaryjoint 36 a (first conductive portion) and the rotary joint 1036(insulating seal portion) are paired and stacked to form a rotationcolumn. For example, when four-pole potentials are supplied to thesubstrate holder, the rotary joint 1036 is inserted between adjacentones of the four rotary joints 36 a to form part of the rotation column25.

The power supply device according to each of the first and secondembodiments is applicable to the substrate processing apparatus in whichthe substrate holder is turned in a state in which the normal to thesubstrate holding surface of the substrate holder is perpendicular tothe gravity direction, thereby processing the substrate. Power can bestably supplied to the substrate holder having a plurality ofelectrodes.

The present invention is not limited to the above-described embodiments,and various changes and modifications can be made within the spirit andscope of the present invention. Therefore, to apprise the public of thescope of the present invention, the following claims are made.

REFERENCE SIGNS LIST

1: ion beam etching apparatus, 3: vacuum vessel, 5: ion beam source, 7:substrate stage, 7 a: substrate holding portion (substrate holder), 7 b:rotation support portion, 9: shutter device, 23: dielectric plate, 24:electrostatic chuck, 25, 45 a, 101 a, 101 b: rotation column, 26: vacuumseal mechanism, 27: rotation driving device, 28 a, 28 b: electrode, 29a, 29 b: power supply rod, 30: power supply mechanism, 30 a, 30 b:divided region, 31 a, 31 b: insulating member, 32: rotation cylinder, 33a, 33 b: cable, 38 a, 38 b, 45 b: housing, 36, 36 a, 36 b, 1036: rotaryjoint, 37 a, 39 a, 37 b, 39 b: conductive annular member, 59: coolingwater drain pipe, 63: cooling water supply pipe, 64: insulating member,71 a: first voltage power supply, 71 b: second voltage power supply,102, 104: O-ring, 103: rubber seal member, 1037, 1039: annular member,130: annular portion, 135, 137: elastic member, 138: annular portion(seal portion), 139: annular portion, 201, 202: space, 300, 310: dryingair inlet port, 320, 330: drying air outlet

1. A power supply device comprising: a substrate holder capable ofholding a substrate; a column connected to the substrate holder andincluding a first conductive column portion and second conductive columnportion; a housing rotatably supporting the column and including a firstconductive housing portion and a second conductive housing portion; afirst conductive portion configured to supply a first voltage from thefirst conductive housing portion to the first conductive column portion;a second conductive portion configured to supply a second voltage fromthe second conductive housing portion to the second conductive columnportion, the second conductive portion being insulated from the firstconductive portion; a first power supply member connected to the firstconductive column portion and configured to supply the first voltage tothe substrate holder; and a second power supply member connected to thesecond conductive column portion and configured to supply the secondvoltage to the substrate holder, wherein a first space in contact withthe first conductive portion and capable of flowing a coolant and asecond space in contact with the second conducive portion and capable offlowing the coolant are formed in a gap between the column and thehousing, and the power supply device further comprises a separatingsection configured to separate the first space from a member appliedwith the second voltage and separating the second space from a memberapplied with the first voltage.
 2. The power supply device according toclaim 1, wherein the column further comprises an insulating columnportion arranged between the first conductive column portion and thesecond conductive column portion, the housing further comprises aninsulting housing portion arranged between the first conductive housingportion and the second conductive housing portion, the separatingsection comprises an insulating seal portion arranged between theinsulating housing portion and the insulating column portion andconfigured to seal the coolant, and the first space is formed betweenthe first conductive portion and the insulating seal portion, and thesecond space is formed between the second conductive portion and theinsulating seal portion.
 3. The power supply device according to claim1, wherein the coolant supplied to one of the first space and the secondspace flows through the substrate holder and is drained from the otherof the first space and the second space.
 4. The power supply deviceaccording to claim 1, wherein the column comprises a first channelconfigured to supply the coolant to the substrate holder and a secondchannel configured to drain the coolant from the substrate holder, thefirst channel being connected to one of the first space and the secondspace, and the second channel being connected to the other of the firstspace and the second space.
 5. The power supply device according toclaim 2, wherein the first conductive portion, the second conductiveportion, and the insulating seal portion are spaced apart from eachother in a rotation axis direction of the column.
 6. The power supplydevice according to claim 2, wherein the first conductive portion, thesecond conductive portion, and the insulating seal portion are spacedapart from each other in a radial direction of the column.
 7. The powersupply device according to claim 2, wherein the first conductive portioncomprises a first rotation conductive member arranged in the firstconductive column portion and a first fixed conductive member arrangedin the first conductive housing portion and in slidable contact with thefirst rotation conductive member, the second conductive portioncomprises a second rotation conductive member arranged in the secondconductive column portion and a second fixed conductive member arrangedin the second conductive housing portion and in slidable contact withthe second rotation conductive member, and the insulating seal portioncomprises a rotation insulating member arranged in the insulating columnportion and a fixed insulating member arranged in the insulating housingportion and in slidable contact with the rotation insulating member. 8.The power supply device according to claim 1, wherein a channelconfigured to supply a gas to an interior of a space opposite to thefirst space through the first conductive portion is formed.
 9. The powersupply device according to claim 1, wherein a channel configured tosupply a gas to an interior of a space opposite to the second spacethrough the second conductive portion is formed.
 10. The power supplydevice according to claim 8, wherein a channel configured to collect agas supplied to an interior of a space opposite to the first spacethrough the first conductive portion is formed.
 11. The power supplydevice according to claim 9, wherein a channel configured to collect agas supplied to an interior of a space opposite to the second spacethrough the second conductive portion is formed.
 12. The power supplydevice according to claim 1, further comprising: a first rotationdriving device configured to rotate the housing about a first rotationaxis; and a second rotation driving device configured to rotate thesubstrate holder about a second rotation axis in a directionperpendicular to the first rotation axis.
 13. A vacuum processingapparatus in which the substrate holder is arranged in a vacuumprocessing chamber and includes an electrostatic attraction deviceconfigured to hold a substrate subjected to a predetermined vacuumprocess, wherein power is supplied to the electrostatic attractiondevice through a power supply device defined in claim 1.